This invention is related to a medical boot and a supporting splint for treating or avoiding decubitus ulcers, especially for patients with heel, toe and foot pressure ulcers.
Decubitus ulcers are pressure sores commonly found in patients of hospitals and other institutions. Such sores add considerably to patient nursing time and to the cost of medical care. Complications associated with pressure sores may be life-threatening. Many devices are known in the prior art, some of which are commercially-available, for treating or avoiding such sores, however, they are frequently unsatisfactory because they are not responsive to the underlying causes of the sores.
Pressure sores can develop over any bony prominence or area subjected to prolonged pressure, such as on the heel. A pressure gradient in the area of the sore is one of the causes of such sores. Blood vessels, muscles, subcutaneous fat and skin frequently are pressed between a bone and a sleeping surface. Pressure is transmitted from the body toward the bone. Soft tissue compressed between a bony prominence and a firm external surface is susceptible to tissue destruction. The external surface produces pressure, and the bone produces counter pressure. These opposing surfaces result in a pressure gradient involving the tissue between the external surface and the skeletal anatomy involved. The greatest tissue destruction is beneath the skin surface.
Another factor that contributes to the mechanical destruction of tissue is a shear effect, which mainly occurs in deep tissues. The tissue attached to the bone is pulled in one direction because of the body weight while the surface tissue sticks to the bed linen and remains stationary. The body skeleton actually slides inside the skin. A shearing force can occur when patients are dragged along the surface of the sheets during repositioning.
Friction is another factor that develops pressure sores. Two surfaces moving across one another create friction. Friction commonly occurs in patients who are unable to lift themselves sufficiently for repositioning. If a patient is pulled across the bed linen, the outer protective layer of skin may be rubbed away by abrasion. This mechanical wearing away of surface tissue increases the potential for deeper tissue damage. Patients who have appliances that rub against the skin are also at high risk for tissue damage by friction.
Other factors such as exposure to moisture can macerate the skin. Maceration contributes to pressure ulcers because the excessive moisture softens the connective tissue.
Many commercial devices are available on the market for avoiding or treating pressure sores. These include for example, "The Vascular Boot" available from Lunax Corporation of Bloomfield Hills, Mich.; the Jerome 0355 "Bed Boot" available from Orthopedic & Sports Medicine; the "Rooke Vascular System"; the "Foot Waffle" available from EHOB Inc. of Indianapolis, Ind.; the "Heeler" available from BioMedical Systems; the "Cradle-Lite" available from Bird and Cronin Inc.; the Posey "Heel Protector" and "Foot Guard"; the "L'Nard Multi-Podus Orthosis System" available from L'Nard Restorative Concepts Inc. of Clearwater, Fla.; the "California Ankle Foot Orthosis--C.A.F.O." available from Capra Resources; the "E-Z Boot" foot splint available from Medassist-Op Inc. of Palm Harbor, Fla.; the "Pressure Relief Ankle Foot Orthosis" available from Anatomical Concepts, Inc. of Boardman, Ohio; and the "Pillo-Boot" Lower Leg Positioning Device available from BioPlasty Inc. of St. Paul, Minn.
Other similar devices have been disclosed in the prior art, including U.S. Pat. No. 4,478,214 which was issued Oct. 23, 1984 to William D. Lamont for "Medical Boot Apparatus and Methods of Constructing and Utilizing Same"; U.S. Pat. No. 4,197,845 which was issued Apr. 15, 1980 to Edward G. Browning for "Device for Prevention of Decubitus Ulcers on the Human Heel"; U.S. Pat. No. RE 3390 which was re-issued Oct. 17, 1989 to Ramon Berguer for "lsothermic Protective Boot"; U.S. Pat. No. 2,911,657 which was issued Nov. 10, 1959 to George W. Streeter III for "Leg and Foot Rest"; U.S. Pat. No. 3,511,233 which was issued May 12, 1970 to Elbert Holy Jr. for "Foot Protector"; U.S. Pat. No. 4,076,022 which was issued Feb. 28, 1978 to James Walker for "Therapeutic Foot and Leg Protector"; U.S. Pat. No. 3,606,884 which was issued Sep. 21, 1971 to Mary A. Peter for "Foot-Boot Apparatus"; and U.S. Pat. No. 4,813,162 which was issued Mar. 21, 1989 to Evelyn D. Gliege and Edward A. Martin for "Device for Receiving an Orthotic Insert".